Planet-gear carrier



Jan. 8, 1963 H. J. scHwERDHFl-:R 3,071,985

PLANET-GEAR CARRIER Filed Feb. 2:5, 1962 F/GE KM M

United States Patent lilice dlldh Patented Jan. 8, 1963 3,071,986 PLANET-GEAR {ARRER Hans tloacizirn Schwerdhrer, Schweinfurt (Main, Germany, assigner to Fichtel d; Sachs AQ., Schweinfurt (li/lain), Germany, a corporation of Germany Filed liteit. 23, 1962, Ser. No. 175,154 Claims priority, application Germany Ech. 24, 1961 Claims. (Cl. 7l-ll2) rEhe present invention relates to a carrier for the planet gears which l'orm a part of the planetary gearing in `a multi-speed coaster brake and to methods for making such planet carriers.

The planet carrier of the present invention provides unusual strength and compactness as compared with conventional planet carriers for this type of service. Such a coaster brake is disclosed in my Patent No. 2,895,576 issued on July 2l, 1959. The usual planet carrier has a body including a flange portion to which the shafts for the planet gears are attached, one end of each shaft being rigidly secured to the flange portion. In the high speed condition of the gearing, the planet gears are driven by torque applied to the free ends of the shafts. As a result, the shafts must be large enough and sufficiently securely fastened to the flange portion of the carrier body to withstand the bending moments accompanying torque transmitted to the planet gears from the free ends of their shafts. This condition prevails even when a common ring member interconnects the free ends of the shafts.

ln the present invention, a common ring member is permanently mounted on integrally formed bosses which extend axially from the liange portion of the carrier body. The bosses are shouldered to provide stud portions which are riveted over to secure the common ring member to the carrier body. After assembly, axially aligned holes are drilled in the flange portion and ring member to receive the shafts for the planet gears, whereafter the assembly is hardened. After hardening, these holes are precision honed and other critical finished surfaces are ground. The planet gears are then positioned between the liange portion of the body and the ring member. The shafts are then inserted in the gears. The shafts are held in place by a retaining collar and a snap ring.

Various obiects, features and advantages of the invention will become apparent upon reading the following specification together with the accompanying drawing forming a part hereof.

Referring to the drawing:

FlGURE l is an end view of a planet carrier embodying the invention with the planet gears and their shafts removed.

FIGURE 2 is a side elevational view of the planet carlrier of FlG. l, partly broken away to illustrate details of construction.

FIGURE 3 is a View in axial section of the body portion of the planet carrier of FG. 1.

yl `iGURE 4 is a view in axial section of the planet carrier of FIG. l, completely assembled with the planet gears and their shafts in place.

FIGURE 5 is an enlarged fragmentary view in axial section showing the connection between one of the bosses and the ring member.

Referring to FIGS. 1 and 2, the planet carrier comprises a body portion designated generally as and a ring member designated generally as 12. The body portion l@ has an axially extending cylindrical bore 13 formed therein which freely revolubly receives the stationary main shaft (not shown) of the coaster brake. The body portion 10 includes a hub portion 14 which is encircled by a groove 1S of semicircular cross-section. The body portion it) also includes a flange portion 16. A regularly circularly arranged series of bosses 18 is integrally formed on the flange portion 16. The bosses 18 are symmetrically arranged with respect to the rotational axis of the planet carrier 1h, 12 as defined by the bo-re i3.

Each boss 18 extends axially outwardly from the flange portion 16 and is shouldered near its free end to provide an axially outwardly extending stud portion 20 of circular cross-section the axis of which is parallel to the rotational axis of the body portion 10. The ring member 12 has a first regularly cireularly arranged series of holes 22 (FlG. 5) formed therein which are tapered :at 24 to flare outwardly. The holes Ztl in the ring member 12 are arranged to receive the stud portions 2li of the bosses 1S. When assembled in a riveting press, indentations 26 are `formed in the free ends of the stud portions 2li so that they beco-me enlarged and fill the flaring portions 24 of the holes 26. The ring member 12 is thus positively and permanently secured to the bosses 13.

After assembly, a series of regularly circularly arranged holes 28 is drilled in the flange portion 16 each intermediate two adjacent ones of the bosses 18. A second regularly arranged series of holes 3ft (FIG. 2) is also drilled in the ring member 12. Each hole 3d is in axial alignment with one of the larger holes 2S in flange portion 15. The larger hole 3i? is dimensioned to receive the larger diameter portion 32 of planet gear shaft designated generally as 33. The shaft 33 is shouldered to provide a smaller diameter portion 34 which lits into the axially aligned smaller hole 3i) formed in the ring member 12. The reduced diameter portions 34 of shafts 33 are slightly tapered to provide a positive lit without play in the holes The larger diameter portions 32 have a sliding tit in the holes 2S with a minimum of play. The shafts 33 are held against axial movement out of the holes 28 and 34 by a retaining collar 36 which partially covers the holes 2S. The retaining collar 36 is held in place by a snap ring 33 fitted in the groove 15. Planet gears 40 are freely revolubly mounted on the larger diameter portions 32 of the shafts 33 between the flange portion 16 and the ring member 12.

internal spline teeth i2 are formed on the ring member l2. and are adapted for engagement with an axially displaceable coupling member, as shown in application Serial No. 149,584 filed on November 2, 1961. The coupling member has complementary external spline teeth which engage the spline teeth d2 when it is desired to transmit driving torque to the planet gears 4d through the planet carrier in the high speed condition of the coaster brake.

The planet carrier is manufactured in the following manner:

A stack of ring members 12 is machined by a breaching tool to form the spline teeth 42. The first series of holes 3d is also drilled in the stack. The bosses 18 of the body portion 1li are machined to form the stud portions Ztl which fit into the holes 3@ in the ring member 12. A ring member l2 and a body portion 1li are then assembled and riveted together in a suitable press to form a permanent connection as shown in FlG. 5.

After assembly of the body 1t) and ring member 12, the coaxial holes 28 and 3d are drilled using a suitable jig. After the drilling operation has been completed, the assembly is hardened by appropriate heat treatment. After hardening, critical dimensions are obtained by grinding, including a honing of the holes 13, 28 and 30 to bring their internal diameters within the permissible tolerances. The planet gears ttl are then mounted between the flange portion 16 and the ring member 12 and the shafts 33 are inserted. The retaining collar 36 is then slid over the hub portion 14 and the snap ring 38 is positioned in the groove 15 to hold the retaining collar 36 in position. The retaining collar 36, in turn, holds all 3 of the shafts 33 against axial movement out of the holes 28 and 30.

The free end portion of the hub 14 is shown smooth. If desired, for use in a co-aster brake where the braking action is produced by back pedaling, a helical thread may be formed on the outer surface of the hub 14 extending from its free end toward the groove 1S.

While l have shown and described what l believe to be the best embodiment of my invention, it will be apparent to those skilled in the art that various modifications may be made therein without departing from the spirit and scope of the invention as defined inthe appended claims.

What is claimed is:

1. A planet carrier of the class described, comprising: a rotatable body portion including a flange portion; a regularly circularly arranged series of bosses integrally formed on said flange portion, each boss being shouldered to provide an axially extending stud portion of reduced diameter and circular cross-section the axis of which is parallel to the rotational axis of said body portion, said ange portion having a regularly circularly arranged series of holes formed therein each intermediate two adjacent ones of said bosses; a ring member ixedly mounted on said bosses co-ncentrically with said rotational axis, said ring member having a first regularly circularly arranged series of holes formed therein each of which receives one of said stud portions and a second regularly arranged series of holes each in axial alignment with one of said holes in said ilange portion; a shaft extending axially from each hole in said flange portion into an aligned hole of said second series in said ring member; means restraining each shaft against axial movement out of said holes; and a planet gear freely revolubly carried by each of said shafts between said flange portion and said ring member.

2. A planet carrier according to claim 1, wherein an outer end portion of each hole of said first series is enlarged to are outwardly, each stud portion being enlarged at its free end to till said outer end portion of said hole wherein it is received, whereby said ring member is lixedly mounted on said bosses.

3. A planet carrier according to claim 1, wherein said ring member has internal spline teeth formed thereon, said spline teeth being engageable by a complementarily externally toothed coupling member.

4. A planet carrier according to claim 1, wherein the diameter of each hole in said flange portion is different from the diameter of the aligned hole of said second series, and in which each shaft is shouldered intermediate its ends to pro-vide portions of different diameters which t said aligned holes, said shouldering preventing axial movement of said shaft out of said holes in one direction, said restraining means preventing axial movement of said shaft in the direction opposite to said one direction.

5. A planet carrier according to claim 4, wherein the holes of larger diameter are formed in said flange portion and said shouldering abuts said ring member, said restraining means comprising collar means carried by said body portion and which at least partially closes said holes of larger diameter beyond the ends of the larger diameter portions of said shafts.

References Cited in the file of this patent UNITED STATES PATENTS 1,974,230 Armington Sept. 18, 1934 2,093,325 Lansing Sept. 14, 1937 2,656,594 Westling Oct. 27, 1953 2,704,395 Heidegger Mar. 22, 1955 

1. A PLANET CARRIER OF THE CLASS DESCRIBED, COMPRISING: A ROTATABLE BODY PORTION INCLUDING A FLANGE PORTION; A REGULARLY CIRCULARLY ARRANGED SERIES OF BOSSES INTEGRALLY FORMED ON SAID FLANGE PORTION, EACH BOSS BEING SHOULDERED TO PROVIDE AN AXIALLY EXTENDING STUD PORTION OF REDUCED DIAMETER AND CIRCULAR CROSS-SECTION THE AXIS OF WHICH IS PARALLEL TO THE ROTATIONAL AXIS OF SAID BODY PORTION, SAID FLANGE PORTION HAVING A REGULARLY CIRCULARLY ARRANGED SERIES OF HOLES FORMED THEREIN EACH INTERMEDIATE TWO ADJACENT ONES OF SAID BOSSES; A RING MEMBER FIXEDLY MOUNTED ON SAID BOSSES CONCENTRICALLY WITH SAID ROTATIONAL AXIS, SAID RING MEMBER HAVING A FIRST REGULARLY CIRCULARLY ARRANGED SERIES OF HOLES FORMED THEREIN EACH OF WHICH RECEIVES ONE OF SAID STUD PORTIONS AND A SECOND REGULARLY ARRANGED SERIES OF HOLES EACH IN AXIAL ALIGNMENT WITH ONE OF SAID HOLES IN SAID FLANGE PORTION; A SHAFT EXTENDING AXIALLY FROM EACH HOLE IN SAID FLANGE PORTION INTO AN ALIGNED HOLE OF SAID SECOND SERIES AGAINST AXIAL MOVEMENT OUT OF SAID HOLES; AND A PLANET GEAR FREELY REVOLUBLY CARRIED BY EACH OF SAID SHAFTS BETWEEN SAID FLANGE PORTION AND SAID RING MEMBER. 